What is echinococcosis?

Echinococcosis is a parasitic disease caused by the larval stage of Echinococcus tapeworms. Two species cause most human disease: E. granulosus (causing cystic echinococcosis, CE — "hydatid disease") and E. multilocularis (causing alveolar echinococcosis, AE). Humans are accidental intermediate hosts — infected by ingesting tapeworm eggs from contaminated environments, food or water. CE forms slowly growing fluid-filled cysts in the liver and lungs; AE invades the liver aggressively like a malignancy.

How is CE (hydatid disease) transmitted?

The CE transmission cycle: adult E. granulosus tapeworms live in dogs' intestines → eggs shed in dog faeces → dogs defecate on pastures, water sources and around homes → humans ingest eggs (from unwashed hands, contaminated vegetables, water or direct contact with dogs) → larvae hatch in the intestine → larvae travel via blood to the liver (65-70%) and lungs (25%) → form hydatid cysts. Sheep, cattle and goats are the intermediate hosts in agricultural settings; infected offal fed to dogs sustains the cycle.

What are the symptoms?

CE: cysts grow slowly (1-3cm/year) and are often asymptomatic for years to decades. When large: abdominal pain (liver cysts), cough and chest pain (lung cysts), jaundice (biliary compression). Cyst rupture is the most serious complication — releasing protoscolices into the body cavity causing anaphylaxis and disseminated secondary hydatidosis. AE: presents like a slow-growing liver tumour — vague abdominal pain, jaundice, weight loss. Diagnosis usually late (mean 5-15 years of asymptomatic growth). AE at diagnosis is typically inoperable in approximately 50% of cases.

CE treatment is guided by the WHO CE ultrasound classification (CE1-CE5). Active cysts (CE1, CE3a): PAIR (Percutaneous puncture, Aspiration, Injection of hypertonic saline, Re-aspiration) plus albendazole — now preferred over surgery for accessible cysts, with comparable efficacy and less morbidity. Multivesicular active cysts (CE2, CE3b): typically require surgery (partial cystectomy or pericystectomy). Inactive cysts (CE4, CE5): watch and wait; albendazole if uncertainty. All patients receive albendazole perioperatively.

AE requires: radical surgery (hepatectomy — curative if complete resection possible, R0 — approximately 50% of cases); plus albendazole (indefinitely if radical resection incomplete or not possible; for 2 years minimum after radical R0 resection). For inoperable AE, indefinite albendazole is the only option — stabilising disease but rarely curing it. Liver transplantation has been performed in selected cases of advanced AE. Long-term PET-CT and serology monitoring is required.

Is echinococcosis present in Georgia?

Yes — Georgia and the South Caucasus region are highly endemic for cystic echinococcosis (CE), primarily E. granulosus in the dog-sheep transmission cycle. CE is a significant surgical cause of morbidity in Georgia — hydatid cysts of the liver and lung are encountered regularly in Georgian surgical practice. PHIG coordinates CE surveillance and control efforts. The Georgian Medical Journal has published research on echinococcosis in Georgia.

How can echinococcosis be prevented?

CE prevention: regular deworming of dogs (praziquantel monthly/quarterly); preventing dogs from accessing raw offal (proper abattoir waste disposal and cooking of offal); hand hygiene (handwashing after contact with dogs); and public education. AE prevention: avoiding direct hand-mouth contact with fox faeces; washing berries and mushrooms from fox habitats; no raw feeding of dogs. Vaccination of sheep (EG95 vaccine) is effective for CE prevention in livestock — breaking the animal-to-dog transmission cycle.

What is the One Health dimension?

Echinococcosis is a paradigm One Health problem: human disease is driven by animal (dog, fox) reservoir management and livestock husbandry practices. Effective CE control requires: veterinary medicine (dog deworming programmes, livestock vaccination); human medicine (surgical and imaging capacity); environmental management (abattoir waste disposal, rodent control for AE); and public education. Countries that have sustained dog-deworming and livestock vaccination programmes (Iceland, New Zealand, Cyprus, parts of Patagonia) have virtually eliminated CE.

How does GMJ News cover echinococcosis?

GMJ News covers WHO echinococcosis data, CE burden in the South Caucasus, PAIR procedure evidence, AE management, and One Health prevention approaches. CE is directly relevant to Georgian public health and surgical practice — a PHIG priority and Georgian Medical Journal subject.

Home › Topics › Echinococcosis (Hydatid Disease)

Echinococcosis (Hydatid Disease)

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

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Echinococcosis — caused by the larval stage of Echinococcus tapeworms — encompasses cystic echinococcosis (CE, hydatid disease — caused by E. granulosus from dogs and livestock) and alveolar echinococcosis (AE — caused by E. multilocularis from foxes and rodents): together they cause approximately 19,000 deaths per year and the loss of over 3 million disability-adjusted life years (WHO). AE is particularly deadly — behaving like a slow-growing liver cancer — with 94% mortality within 10 years without treatment. Both are zoonoses requiring One Health approaches: CE is prevalent across the Mediterranean, Middle East and Central Asia, directly relevant to the South Caucasus.

Key messages

19,000 deaths per year

Echinococcosis — caused by the larval stage of Echinococcus tapeworms — causes approximately 19,000 deaths per year and over 3 million DALYs lost annually. It is a zoonotic disease requiring One Health approaches involving human medicine, veterinary medicine and environmental management (WHO).

Two diseases — very different courses

Cystic echinococcosis (CE, hydatid disease — E. granulosus) forms slowly growing cysts in the liver and lungs, often asymptomatic for years. Alveolar echinococcosis (AE — E. multilocularis) is far more aggressive — behaving like an invasive liver malignancy with 94% untreated mortality within 10 years.

Dogs and sheep (CE); foxes and rodents (AE)

CE is transmitted through dogs as definitive hosts and sheep/cattle as intermediate hosts — eggs passed in dog faeces contaminate the environment, ingested by humans or livestock. AE is transmitted through red foxes, coyotes and wolves as definitive hosts and rodents as intermediate hosts.

Surgery and PAIR

CE treatment: PAIR (Percutaneous puncture, Aspiration, Injection of hypertonic saline, Re-aspiration) combined with albendazole — now preferred over surgery for many CE types. AE treatment: radical surgery (when resectable) + albendazole; albendazole alone (indefinitely) when not resectable.

Endemic in Mediterranean and Central Asia

CE is hyperendemic across the Mediterranean basin (including Georgia and the South Caucasus), Central Asia, South America and East Africa. AE is endemic in Central Europe, Central Asia, China and North America.

WHO 2030 control target

WHO targets 90% reduction in human CE incidence through dog deworming, improved abattoir practices and public education across 8 priority countries by 2030.

Key statistics

19K

echinococcosis deaths/year

WHO

3M+

DALYs lost/year

WHO

94%

mortality in 10 years without AE treatment

WHO

2-3M

people with CE requiring treatment

WHO/GBD

WHO 2030 priority countries for CE control

WHO NTD Roadmap

Caucasus

region — Georgia is CE endemic

WHO/OIE

Cystic echinococcosis incidence per 100,000 population — WHO endemic regions

Source: WHO. Central Asia, South America and East Africa have the highest rates.

Glossary of key terms

Echinococcus granulosus
WHOThe dog tapeworm — adult worms (3-6mm) in dogs' intestines shed eggs in faeces. Humans (and sheep, cattle) ingest eggs from contaminated environments; larvae form hydatid cysts in the liver (65-70%), lungs (25%) and other organs. The cysts grow slowly — becoming symptomatic after years to decades.

Echinococcus multilocularis
WHOThe fox tapeworm — adult worms in foxes shed eggs; rodents (voles, mice) are normal intermediate hosts. Humans are accidental dead-end hosts — larval tissue invades the liver (primarily) and spreads like a malignancy. Extremely aggressive without treatment.

PAIR procedure
WHOPercutaneous Aspiration, Injection of hypertonic saline/ethanol, Re-aspiration — the WHO-recommended non-surgical CE treatment for appropriate cyst types (CE1, CE3a). Combined with albendazole (started 4+ days before procedure). Comparable efficacy to surgery with lower morbidity.

Albendazole
WHO EMLThe primary pharmacological treatment for echinococcosis — a benzimidazole anthelmintic that impairs parasite glucose uptake and is selectively active against Echinococcus larvae. Required as adjunctive therapy with PAIR or surgery; sole therapy for inoperable AE (indefinite treatment).

Hydatid cyst
WHO/RadiologyThe larval cyst of E. granulosus — a fluid-filled structure with an outer pericyst (host-derived) and inner germinal layer (parasite-derived), which produces brood capsules, protoscolices (future tapeworm heads) and daughter cysts. Diagnosis by ultrasound (WHO CE classification).

WHO CE ultrasound classification
WHO/IWGEThe WHO Informal Working Group on Echinococcosis (IWGE) standardised CE classification — CE1 (active, unilocular); CE2 (active, multivesicular — honeycomb); CE3a-b (transitional — detached laminated membrane); CE4-5 (inactive, solid/calcified). Stage guides treatment choice.

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Echinococcosis (Hydatid Disease)

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